Fluid-pressure governor.



H. W. CHENEY.

FLUID PRESSURE GOVERNOR.

APPLICATION FILED MAR. 27, 1909.

1,011,918, y Patented De0.19,1911.

2SHEETS-SHEET 1.

H. W. CHENEY.

FLUID PRESSURE GOVERNOR.

AIPLIGATION FILED 1113.27, 1909.

1,011,918, Patented Dec. 19,1911.

2 SHEETSSHEET 2.

UMTED sTATEs PATENT oEEIcE.

HERBERT W. CHENEY, F MILWAUKEE, WISCONSIN, ASSIGNOR T0 ALLIS-GHALMEBSCOMPANY, A CORPORATION 0F NEW JERSEY.

FLUID-PRESSURE GOVERNOR.

Specification of Letters Patent.

Application led March 27, 1909. Serial No. 486,239.

To all whom'it may concern:

Be it known that I, HERBERT W. CHENEY, a citizen of the United States,residing at Milwaukee, in the county of Milwaukee and State ofWisconsin, have invented certain new and useful Improvements in Fluid-Pressure Governors, of which the following is a full, clear, and exactspecification.

This invention relates to governors for fluid compressors, andparticularly to that type of governor which includes an electric switchtogether with suitable means for operating the switch so as to close oropen the circuit of an electric motor which drives the compressor, whenthe fluid pressure varies beyond certain predetermined limits.

The object of the invention is a provision of a governor which iseffective and reliable in operation, but which consists of few parts andis very simple in construction and durable.

The invention may be briefly summarized as consisting in certain noveldetails of construction and colnbinations and arrangements of partswhich will be described in the specification and setforth in theaccompanying claims. Y f

Reference is had to the accompanying sheets of drawings in which- Figure1 is a sectional view taken through a governor constructed in accordancewith my invention, parts being broken away for the sake of clearness,and the switch being here shown open; Fig. 2 is a similar view of partof the governor, the switch being here shown closed; Fig. 3 is atransverse sectional view taken substantially along the line 3%?) ofFig. 1, looking in the direction indicated by the arrow; Fig. 4 is afragmentarytransverse sectional view 'subst-antally along the line 4-4of Fig. 3 looking in the direction indicated by the arrow.

{eferring to the figures of the drawing, 10 represents a casting whichincludes a cylinder or casing 11 and a flat base 11 at one end ofthecylinder for supporting part of the governor mechanism. At theopposite end of the cylinder is a tightly clamped flexible diaphragm 12which is preferably made of strong rubber and is adapted to be shiftedback and forth by variations vin fluid pressure so as to operate thegovernor, the diaphragm being clamped between the open end of thecylinder and a cap 13 which is secured to the cylinder.

Between one side of the diaphragm and cap is a cavity or chamber 14which will -be connected to the fluid reservoir or to the pres suresystem by a pipe (not shown) adapted to'be secured into a socket 15. Onthe opposite side of the diaphragm and engaging the latter yso as to beshifted inward or outward by variations in the flexure thereof is a heador enlarged portion 1G of a plunger having a shank 17 which extendsthrough the cylinder and has its free end extending through an opening#in the .base 11a. The movement of the plunger and of the diaphragm 12 isresisted by a rather heavy coil spring 18 which surrounds the shank 17of the plunger and bears against the enlarged portion 1G thereof and adisk 19 which may be adjusted by set screws 2() extending through thebase 11a of the casting and engaging the disk 19. By adjusting thesescrews in the well known manner, the high and low limits of fluidpressure may be varied. The outer end of the plunger 17 is provided witha reduced portion 2l and with a pair of shoulders or flanges 22 and 9.3between which the end of a lever, to be referred to presently, is held,and the lat-ter of which serves by engagement with a block 23 secured tothe top of the base, to limit the inward movement of the plunger.

The major portion of the mechanism of the lgovernor is held or clampedbetween parallel adjacent sides 24 and 25 of a frame which is preferablypunched from sheet metal and is secured to the base 118L by means ofscrews 26.

At 27 is shown a switch lever which is pivotally supported by means of apin 28 extending transversely between the sides of the frame, this leverextending on both sides of its pivotal support and including an arm 29which is pivotedj and yieldingly supported on the main portion of thelever and which carries at its free end a. movablev switch contact 30.This arm 29 extends through a slot in an arcing chute 31, which ofconductors 34 and 35 (to the motor, not shown) and to the blow-outmagnet 3G having pole shoes 37 and 38 located on opposite sides of thearcing chute and on opposite sides of the contacts 30 and 33 so that theflux may extinguish the arc.

Before describing in detail the mechanism by which the switch lever is"operated, it may be stated that by the mechanism which l have provided,the switch lever is held stationary, so that it cannot be prematurelyclosed or opened, by means of the spring-pressed holding member ordetent, and is released by a lost motion device operated by the plungeror the diaphragm and designed to shift the holding member1 so as topermit the lever to be moved in one direction or the other by one of twosprings provided for this purpose, one spring being compressed when thepressure rises and serving to open the switch when the pressure reachesthe predetermined high limit, and the other being compressed when thepressure falls and serving to close the switch when the pressure reachesthe predetermined low limit.

Referring now again to the figures of the drawings, it will be seen thatthe rear end 37 of the switch lever, or the end on the side of thesupporting pin 28 opposite to the Contact 30 is enlarged and is providedwith a socket or cavity containing a coil spring 38 and a detent orlatch, in this case in the form of a ball 39 which is pressed upward bysaid spring. This spring-pressed ball is adapted to coperate with ablock 40 to hold the switch in either its closed or open position, thisblock having two sockets 41 and 42 which are so located and are of sucha size that when the switch is closed the ball will be forced by thespring into the upper socket 41, the ball extending a sutlicientdistance into the socket to hold the switch in its closed position, andwhen the switch is open the ball is forced by the spring a suitabledistance into the socket 42 to hold the switch lever in its openposition. A pin 27L extending transversely between the sides of theframe is adapted to be engaged by the lever to limit the openingmovement of the switch and to prevent the ball passing beyond the socket42 when the switch is opened. This ball is adapted to be shifted fromthe sockets by means of a lost motion device in the form of an arm orstrip 43 which is adapted to slide longitudinally through a slot 44provided centrally in the block 40 and intersecting the sockets 41 and42. This arm is pivotally connected at its lower end to one end of alever 45 which is mounted upon a pin 46 extending between the sides ofthe frame adjacent the outer end of the shank 17 of the plunger, the pin4G being connected to the lever intermediate the ends of the latter. Theopposite end of the lever 45 is bifurcated and straddles the reducedportion 21 of the shank 17 of the plunger, the free ends of the slottedportion of the lever being somewhat rounded and being located betweenthe shoulders 22 and 23 so that when the plunger is shifted eitheroutward or inward with respect to the cylinder 11, the lever 45 and thearm 43 will be shifted.

The portion of the arm 43 extending through the block 40 is providedwith a notch or recessed portion, the ends of which are inclined so asto form two spaced cam faces 47 and 48, the upper cam face 47 beingdesigned to engage the ball 39 and to move the same from the socket 41when the arm 43 is moved downward, and the cam face 48 being designed toengage the ball and move the same from the socket 42 when the arm 43 ismoved upward. These two cam faces will be spaced apart a suitabledistance which will govern to a considerable extent the range of fluidpressure in the compressor cylinder or reservoir. Other means forvarying the range of pressure will be explained later.

In order that the switch may be opened with a quick movement when theball is moved from the upper socket 41, and quickly closed when the ballis lifted from the socket 42, I have provided the following mechanismPivotally connected to the lever 45 between the pin 46 and theconnection of the'lever with the arm 43 is a rod 49 which is designed tobe moved longitudinally by the lever 45 and which passes loosely throughan opening in the switch lever 27 between the pin 28 and the enlargedsocketed end 37 and loosely through a pin 5() extending between thesides of the frame near the outer or upper part thereof. Carried by therod 49 near the two ends thereof are two abutments in the form ofcollars 51 and 52, the position of the upper collar 51 being adjustableby means of nuts 51a engaging a threaded portion of the rod, and looselymounted upon the rod 49 and bearing against opposite sides of the leverare two sleeves 53 and 54 respectively. Surrounding the rod 49 betweenthe collar 51 and the sleeve 53 is a coil spring 55 which, as will beexplained, is compressed when the pressure rises, and is designed toopen the switch when the pressure reaches a predetermined value, andbetween the collar 52 and the sleeve 54 is a coil spring 56 which iscompressed when the fluid pressure falls and again closes the switchwhen the fluid pressure is reduced to a predetermined value.

The mechanism of the governor mounted upon the portion 11 of thecylinder casting is inclosed in a casing which is preferably made ofnon-magnetic material and consists of two parts 57 and 58 which may besecured to the casting in any desired manner and held together by asuitable latch, a portion of which is shown at 59.

The governor, which may be located in any desired position relative tothe compressor will be adjusted by means of screws 20 so as to operateat a desired maximum or minimum pressure which may vary between anydesired limits, say for example, between 90 pounds and 100 pounds. Therange of pressure or the vdifference between the maximum and minimumpressures may be varied by adjusting the nuts 51* on the upper end ofrod 49 and hence the degree of compression of coil spring 55. It mayalso be varied by changing the distancebetween the cam faces 47 and 48on arm 43.

Assuming that the switch is open and the motor which drives thecompressor is stationary, the plunger will move gradually inwardrelative tothe cylinder as the fluid pressure is decreased and as thediaphragm becomes less flexed. As the plunger moves inward, the arm 43and rod 49 are gradually moved outward compressing coil spring 56. Whenthe fluid pressure falls to a predetermined value, the cam face 48engages the ball 39 and moves the same from the socket 42 so as torelease the lever 27 and permit the spring 56 to close t-he switch.

WVhen the switch is closed, the motor will be started and the fluidpressure will be again built up. 'As the fluid pressure increases thediaphragm 12 will be moved outwardly against the tension of the coilspring 18 moving the plunger upward and causing the rod 49 and the arm43 to move inward. While this is taking place, coil spring 55 is beingcompressed and cam face 47 a proaches the ball 39 which now engages t esocket 41. When the pressure rises to a predetermined value, the camface 47 moves the ball from the socket 41 so as to again release thelever and permit the coil spring 55 to open the switch.

The mechanism which I have described above has proven by practice to beextremely eflicient and reliable, and in fact answers all therequirements of operation and durability, and at the same time iscompact and inexpensive to manufacture.

I do not desire vto be confined to the exact details shown anddescribed, but aim in my claims to cover all modifications which do notinvolve a departure from the spirit and' said switch lever againstmovement during certain ranges of fluid pressure, and means including acam member operated by said plunger after a predetermined movementthereof for releasin the lever so that it can be shifted by one o saidsprings.

2. In a governor for a fluid compressor, a

plunger shifted inward or outward by variations in fluid pressure, aswitch including a switch leverresponsive to the action of said plunger,a pair of springs, one serving to openthe switch and the other to closethe switch, and one being compressed when the plunger is moved in onedirection and the other compressed when the plunger is moved in theopposite direction, means for holding said switch lever against movementduring a certain range of fluid pressure, and means including a cammember operated by 'said plunger after a predetermined movement thereoffor releasing the lever so that it can be shifted by one of saidsprings.

3. In a governor for a fluid compressor, a plunger shifted inward oroutward by variations in fluid pressure, a switch lever responsive tothe action of said plunger, a pair of springs acting on said lever andone serving to shift the lever in one direction and the other to shiftthe lever in the opposite direction, means for holding said leverstationary during a certainl range of movement of said plunger, meansfor compressing one of said springs during said movement, and a lostmotion device having a cam portion operated by said plunger and servingto release the lever after a predetermined movement of the plunger.

4. In a fluid pressure governor, a plunger adapted to be shifted byvariations in fluid pressure, a switch including a pivoted switch lever,means for holding said lever against movement during a certain rangeoffluid pressure, said means comprising a stationary member and a detentcarried by the lever, said member having sockets in which said detent isadapted to be. inserted, and' means operated by said plunger forshifting said detent from said sockets when the high and low limits ofpressureV have been reached so as to release the lever.

5. In a governor for fluid compressors, a movablewall adapted to beshifted inward or outward by variations in fluid pressure, a pivotedswitch lever, means for holding said lever against movement through acertain range of fluid pressure, said means comprising a spring-presseddevice carried by the lever, and a stationary member having sockets inwhich said device is adapted to be inserted, and means for shifting saiddevice from the sockets so as to release the lever comprising a movablemember adapted to be shifted by said movable wall into engagement withsaid spring-pressed device.

6. In -a governor for air compressors, a

plunger adapted to be actuated by variations in fluid pressure, a switchcomprising a pivoted lever, a spring for shifting the lever, aspring-pressed holding device, and a member having a pair of sockets ineither one of which the device is adapted to be inserted so as to holdthe switch in its open or closed position during a definite range offluid pressure, and means operated by said plunger for placing saidspring under stress, and after a certain movement thereof for shiftingsaid holding device from a socket so as to release the lever and permitthe spring to shift the same.

7. In combination, in a governor for fluid compressors, a movable membershifted back and forth by variations in fluid pressure, a switchcomprising a pivoted lever, means for holding said switch lever againstmovement with the switch either closed or open during certain ranges offluid pressure comprising a spring-pressed device carried by the lever,a stationary member having a pair of sockets in which saidspring-pressed device is adapted to, be "inserted, a spring for shiftingsaid lever, and means operated by said pressure actuated member forstoring energy in said spring and for causing the release of said lever.

8. In combination, in a. fluid pressure governor, a plunger adapted tobe actuated by variations in fluid pressure, a switch comprising apivoted switch lever, means for holding said lever against movementduring a certain range of fluid pressure comprising a spring-presseddevice carried by said lever, a stationary member having a pair ofspaced sockets in which said device is adapted to be inserted, and meansoperated by said plunger, when the latter is moved a certain amount inone direction, to shift said spring-pressed device from one of thesockets and to permit the switch to be opened, and when the plunger ismoved a certain amount in the opposite direction, to shift saidspring-pressed device from the other socket to permit the switch to beclosed.

9. In a governor for fluid compressors, a member adapted to be actuatedby variations in fluid pressure, a switch comprising a pivoted switchlever, a pair of springs acting on opposite sides of said lever and whencompressed serving respectively to shift the lever to open and close theswitch, a movable holding latch carried by said lever, a member having apair of Sockets in which the latch is to be inserted so as to hold theswitch against movement during a certain range of fluid pressurevariation, the switch being held closed when the latch is in onesocketand held open when the latch is in an other socket, andan armshifted by said pressure actuated member for moving said latch from thesockets to permit the switch lever to be shifted.

10. In a governor for fluid compressors, a plunger adapted to be shiftedin opposite directions by variations in fluid pressure, a switchcomprising a pivoted switch lever, means for holding said lever againstmovement during a. certain range of fluid pressure variation, said meanscomprising a spring-pressed member carried by the lever and a blockhaving a pair of sockets, one of which the spring-pressed member engagesso as to hold the switch closed, and the other of which thespring-pressed member engages so as to hold the switch open, a springacting on lsaid lever so as to shift the same, and means for storing upenergy in said spring and for shifting said spring-pressed member fromsaid notches comprising a lever connected to the plunger, and an armhaving a pair of spaced cam faces adapted to engage said spring-pressedmember.

1l. In a governor for fluid compressors, a plunger adapted to be shiftedby variations in fluid pressure, a switch comprising a pivoted switchlever, a pair of coil springs acting upon opposite sides of said leverand serving respectively to open and close the switch, means for holdingthe switch lever against movement during a definite range of fluidpressure variations, said means comprising a spring-pressed latchcarried by the lever, and a block having a pair of spaced sockets in oneof which the latch is adapted to be inserted so as to hold the switchclosed, and in the other of which it is adapted to be inserted so as tohold the switch open, and means for storing energy in either one of saidsprings and for causing said latch to be withdrawn from either one ofthe sockets depending on the direction in which the plunger is shifted,said means comprising a lever pivotally connected to said plunger, a rodconnected to the lever and passing through said coil springs, and an armconnected to the lever and passing through said block, said arm havingcam faces adapted to engage the latch.

Milwaukee, 1Vis., MarchQ-l, 1909.

In testimony whereof I aliX my signature, in the presence of twowitnesses.

HERBERT 1V. CHENEY. lVitnesses C. CASE, CHAS. L. BYRON.

